Actress Demi Moore’s trip to the emergency room was reportedly spurred by symptoms of a seizure triggered by inhaling the drug nitrous oxide, more commonly known as laughing gas or whippits.

The drug is used legally as an anesthetic and to reduce patients’ anxiety at the dentist’s office, but it is also sold in small cartridges that are intended for use in making whipped cream. These containers can easily be misused by people seeking a high. Although addiction to nitrous is uncommon, its abuse can have serious consequences.

“People who use a lot can [appear to have] something like a seizure,” says Dr. Dennis Bohlin, a Manhattan dentist and expert on addiction in medical professionals, who is himself a former nitrous-oxide addict.

“That happened to me,” he says. “Your face and teeth clench, and you have muscle contractions that can appear like a seizure.”

Bohlin, who has been in recovery for 29 years, says that while nitrous addiction is rare overall, it can be an occupational hazard for dentists and anesthesiologists who have access to it. Among teens, less than half of 1% suffer from abuse or addiction to the entire class of inhalable drugs, which includes household products and gasoline, as well as whippits.

“I just saw it like ‘Miller Time’ at the end of the day,” Bohlin says, referring to a tagline of Miller beer commercials. “It was there and available. I was stressed, and it seemed safer than alcohol. You’re not going to get a DWI while flying in the dental chair, so it was a drug of opportunity.”

The drug was the first agent ever proposed for use as an anesthetic during surgery. The idea was put forth by British chemist Humphry Davy in a book published back in 1800, but it would be another four decades before nitrous oxide was used medically and years more before anesthesia for painful dental extractions and operations became routine. In the meantime, laughing-gas parties had become all the rage in the British aristocracy.

Outside of a medical setting, nitrous oxide can be dangerous, however. At your dentist’s office, the drug is mixed with oxygen when it is delivered through a mask, but when people inhale it from a balloon or a whipped-cream canister at home, it doesn’t allow enough oxygen to get to the brain. “In nitrous oxide, the oxygen is not free for respiration,” Bohlin says. “The biggest danger from whippits is that when you are not using nitrous with oxygen, you can be in a hypoxic state.” If severe hypoxia continues for more than a few minutes, it can lead to brain damage or even death.

The drug also rapidly induces loss of motor control, so if it is taken while standing up, injuries from falls are common. This loss of control usually also has the effect of causing the nonmedical user to drop the balloon, which lets them breathe ordinary air and end the hypoxia.

Nausea is another common side effect. “People can vomit and aspirate the vomit,” says Bohlin, which means they run the risk of choking to death on it. “I know one dentist who died that way.”

Another danger is that long-term chronic nitrous abuse can damage the nerves, causing a condition known as peripheral neuropathy, which involves tingling or loss of sensation and, sometimes, difficulty with movement and coordination. Some research suggests that this results from the ability of nitrous oxide to deplete vitamin B12 levels; high doses of the vitamin are used to treat the condition.

“But no one really knows for sure what causes it,” Bohlin says, adding, “I know one dentist who ended up in wheelchair.”

Bohlin himself developed symptoms of neuropathy when he regularly used nitrous. “My own experience was losing fine motor coordination in my fingers and toes,” a problem that was obviously not conducive to dental practice. Fortunately, he got into recovery and the symptoms receded. “It seems reversible with abstinence for most people,” he says.

One of the challenges for people with nitrous addictions is the rareness of the problem. “You get into a drug like that and you feel unique, and that mitigates against recovery because you feel weird,” he says. In a support group where most people drink or take common street drugs or painkillers, a nitrous addict can stand out.

Bohlin was able to find support groups where he felt welcome. Since then, for decades, he has been able to maintain his own dental practice utilizing the drug for nervous patients (including this reporter), without relapsing.

Beyond misuse and addiction, other hazards of the drug include increased rates of miscarriage for women who are exposed to it regularly, so pregnant workers in Bohlin’s office and pregnant patients are not exposed to the drug.

It’s unlikely that Moore is actually addicted to nitrous oxide — but if she is, she can take comfort in the fact that many have recovered from this unusual drug problem.